In communication systems, channel coding to be transmitted information can prevent interferences occurred in information transmissions, and ensure information or data reliably transmitted to a receiving device. Normally, a sending device encodes the information or data to obtain encoded bits, interleaves the encoded bits, maps the interleaved bits to modulation symbols, and processes and sends the modulation symbols through a communication channel. After receiving the modulation symbols, a receiving device recovers the information or data through a decoding process.
In communication systems using different radio access technologies, different coding schemes are used in order to adapt to different application scenarios.
In a current long term evolution (LTE) protocol, when a length of an information bit sequence carrying uplink control information is greater than or equal to 12 bits and less than or equal to 22 bits, coding is performed using dual LTE-Reed Muller (RM) code (refer to 3GPP TS 36.212 Section 5.2.2 to Section 5.2.4 for details). Recently, in the RAN1#88bis meeting of New Radio (NR), it is agreed that, in the fifth generation (5G) NR schemes, when a length of an information bit sequence is greater than or equal to 12 and less than or equal to 22, the information bit sequence is encoded using a polar code. Polar code is a coding scheme that can gradually reach a channel capacity, and it has excellent decoding performance in wide range of parameters (e.g. code length, bit rate, and signal-to-noise ratio).
In existing polar code coding schemes, parity check (PC) polar code has relatively good performance in terms of code distance and block error rate (BLER) when a successive cancellation list (SCL) algorithm is used, hence having good application potential. In the PC polar coding, an information bit sequence includes K information bits and one or more check bits. Positions of the check bits in the sequence is randomly selected in reliability order, and positions of the K information bits are sequentially selected in descending order of reliability. Therefore, in the PC polar coding, reliabilities of the positions filled by the check bits cannot be ensured, and overall performance of the polar coding scheme may be affected.